Nations rich and poor must invest now to protect against the effects of climate change or pay an even heavier price later, a global commission warned Tuesday.

Spending $1.8 trillion across five key areas over the next decade would not only help buffer the worst impacts of global warming but could generate more than $7 trillion in net benefits, the report from the Global Commission on Adaptation argued.

“We are the last generation that can change the course of climate change, and we are the first generation that then has to live with the consequences,” former UN chief Ban Ki-moon, who chairs the commission, said at the report’s launch in Beijing.

“Delay and pay, or plan and prosper,” he said, sharing a catchphrase from the commission, which is co-chaired by Microsoft founder Bill Gates and World Bank CEO Kristalina Georgieva.

Investing now in early warning systems, climate-resistant infrastructure, mangrove protection, better agriculture and improving fresh water resources would pay for itself several times over, the report said.

Mangroves — tropical tidal water forests — protect, for example, against storm surges and act as nurseries for commercial fisheries, but at least a third of them globally have been uprooted for tourism or aquaculture.

“Global actions to slow climate change are promising but insufficient,” the report stated. “We must invest in a massive effort to adapt to conditions that are now inevitable.”

Without action by 2030, climate change could push more than 100 million people in developing countries below the poverty line, said the report.

In the 25-year history of UN climate negotiations, adaptation has trailed far down the agenda compared with “mitigation”, or the reduction of carbon emissions.

It was long seen as an issue only affecting poor and developing nations.

But recent massive inland flooding and a string of record-breaking hurricanes in the United States, along with ferocious heatwaves in Europe and Japan, have shown that wealth is not an adequate shield.

Dominic Molloy, a co-author of the report and a researcher at the Global Centre for Adaptation, said the new focus should not detract from the need to slash carbon pollution.

“We absolutely need to do both, reduce emissions and adapt,” Molloy told AFP. “The purpose of this commission was to raise the visibility of adaptation, not shift away from mitigation.”

Bob Ward, policy director at the Grantham Research Institute on Climate Change noted that the two are inextricably linked.